The Laramie Energy Technology Center, U.S. Department of Energy, is responsible for evaluating the resources of potential oil and the deposit characteristics of oil shales of the Green River Formation in Colorado, Utah, and Wyoming. While the total oil shale resource represents perhaps 2 trillion barrels of oil, only parts of this total are suitable for any particular development process. To evaluate the resource according to deposit characteristics, a computer system for making resource calculations and geological maps has been established. The system generates resource tables where the calculations have been performed over user-defined geological intervals. The system also has the capability of making area calculations and generating resource maps of geological quality. The graphics package that generates the maps uses corehole assay data and digitized map data. The generated maps may include the following features: selected drainages, towns, political boundaries, township and section surveys, and corehole locations. The maps are then generated according to user-defined scales.